1. Field of the Invention
This invention relates to a method for manufacturing a semiconductor device, more particularly to a method for manufacturing a semiconductor device involving laterally growing and thickening a base layer on a protrusion-patterned layer formed on a substrate, and separating the base layer from the substrate by destroying the protrusion-patterned layer.
2. Description of the Related Art
Referring to FIG. 1, a semiconductor device 13 for epitaxial growth of a gallium nitride-based light emitting diode is conventionally formed by epitaxy growth and laser-assisted lift-off techniques. In detail, the semiconductor device 13 is manufactured by preparing a substrate 11 made of silicon carbide (SiC) or sapphire (α-Al2O3), forming a gallium nitride layer 12 having a thickness of 2 to 10 μm on the substrate 11 through metal organic chemical vapor deposition (MOCVD) techniques, thickening the gallium nitride layer 12 to a thickness greater than 100 μm through hydride vapor phase epitaxy (HVPE) techniques so as to form the semiconductor device 13, and applying a laser to a boundary between the substrate 11 and the gallium nitride layer 12 so as to break bonding therebetween and so as to separate the substrate 11 from the gallium nitride layer 12.
Advantageously, the expensive silicon carbide (SiC) or sapphire (α-Al2O3) substrate 11 used in the above method can be reused, after being subjected to a suitable surface treatment. However, in the above method, numerous dislocations that took place across the gallium nitride layer 12 will extend into the semiconductor device 13 and cause the semiconductor device 13 to have a defect density ranging from 1011 to 1012 μm−2. In addition, the bonding strength of the boundary between the substrate 11 and the gallium nitride layer 12 is not even, and bond-breaking operation of the boundary can cause surface damage to the semiconductor device 13. Hence, production yield of the semiconductor device 13 and quality of the light emitting diode made from such semiconductor device 13 are unsatisfactory.
Therefore, there is a need in the art to provide an economical method for manufacturing a semiconductor device with improved quality.